Process and apparatus for severing flat thermoplastic wefts in looms having a fixed weft supply

ABSTRACT

A vertically movable thermoelectric element is employed to sever thermoplastic weft filaments in a loom.

United States Patent [72] Inventor Ramon Balaguer Golobart [51] Int.D030! 49/70 Calle Valls&Taberner 11, Barcelona, [50] Field 139/302,Spain 303, 122, 123, 127, 122W, 20 [2i] Appl. No. 759,714

[56] References Cited UNITED STATES PATENTS [22] Filed Sept. 13,1968[45] Patented Jan. 19, 1971 w MW 2 Bu n wfl 9 l9 3 3 l l mm m dd nn hh.nN fl CGRZ blt' M i LRSS O 6 88 6 66 9 99 1 H W 4 l 2 3 6 8 72 6 00 744 2 44 3 m 9 l 2 U 8 L.m 0. &SM M m n P 1]] 23 333 [ll [54] PROCESS ANDAPPARATUS FOR SEVER Primary Examiner-Henry S. Jaudon Attorney-Christen &Sabol ING FLAT THERMOPLASTIC WEFTS IN LOOMS HAVING A FIXED WEFT SUPPLY 1Claim, 4 Drawing Figs. [52] ment is employed to sever thermoplastic weftfilaments in a lo PROCESS AND APPARATUS FOR SEVERING FLAT THERMOPLASTICWEFTS IN LOOMS HAVING A FIXED WEFT SUPPLY The present invention refersto a process and apparatus for severing flat weft filaments,particularly polyolefm filaments used in fabrics produced on loomshaving a fixed weft supply.

Until now, the systems used for severing this type of polyolefin weft inlooms having a fixed weft supply effected the severing with knives,shears or scissors, all of them applied near the selvedge of the fabric.These systems did not usually give good results in view of the tendencyof the cutting edges to become blunt and the tendency of the wefts toadhere to the knives, shears or'scisso'rs', with aresulting tendency forthe wefts to tear or rip upon severing. Moreover, all of these systemsare only suitable for the severing of wefts in a loom which makes asingle fabric, and cannot be used in the type of looms which makes twoparallel fabrics at the same time.

The apparatus which is the object of the present invention completelyeliminates these disadvantages, since it does not use cutting elementswhich may run the risks mentioned above, and can be used either inaloom, which makes a single fabric or a loom which makes two parallelfabrics at the same time. y

The apparatus which is the object of the present invention consists inthe application of a thermoelectric element which is susceptible ofbeing heated by means of an electric resistance to a temperature higherthan. the melting point of the thermoplastic material of the flat weft,said thermoelectric element being movably arranged in a verticaldirection so as to move between an operative position and an inactiveposition, to permit the moving of the flat wefts to the lines offormation of the two parallel fabrics; this verticalmovement of thethermoelectric element being effected in synchronization with themovement of the slay comb and the movement of the inserting devices, thethermoelectric element being placed near the edges of the two parallelfabrics, between the two vertical planes formed respectively by thelines of presentation of the wefts to the inserting devices and thelines of displacement of said weft-inserting devices through the twosheds, in such a manner that when the therrnoelectric element is inoperative position, the flat wefts held by the inserting devices andstill joined to the two fabrics makes contact with said thermoelectricelement upon thebeginning of the return movement of the insertingdevices through the sheds, the wefts being severed by fusion of thethermoplastic material.

The apparatus to carry out said process, which is also a part of thepresent invention, comprises a thermoelectric element placed at theextremity of an elbow arm, which can slide in a vertical direction andis connected to a source of electric current, said elbow arm beingguided on a stationary support affixed to a fixed portion of the loom,and actuated by a cam attached on a rotary shaft of the loom incombination with a recoil helical spring.

For better understanding of the invention, an embodiment is describedhereinafter, as a nonlimiting example only, with reference to theattached drawings.

FIG. 1 is a perspective view of the feeding side of a loom having afixed weft supply and manufacturing two parallel fabrics at the sametime, just prior to the grasping of the flat weft strip for each fabricby the inserting devices and prior to the severing of said wefts, withthe thermoelectric element in operative position.

FIG. 2 is a perspective view similar to FIG. 1 after the severing of theflat weft strips has been effected and the flat weft strips are held bythe slay comb, with the thermoelectric element in nonoperative positionfor the new positioning of the wefts for the new actuating of same.

FIG. 3 is a diagrammatic plan view of the feeding side of a loom amoment after the severing of the flat weft strips corresponding to eachfabric has been effected, through the contact of said wefts with thethermoelectric element.

In esefisu ssathsrmqsl s t e e emen h h is pp i from a source ofelectricity (not shown) by cables 2 and 3 and is connected to an elbowarm 4 which is vertically slidable in support 5 joined to the loomframing 6 by means of screws 7 and 8. Inside of said support 5 is houseda recoil spring 9 which tends to maintain element 1 always in operativeposition.

At the lower extremity 10 of elbow arm 4 is rotatably mounted a roller11 which is maintained in contact with a cam 12 attached to a shaft 13of the loom (not shown), through the constant pressure of the helicalspring 9. i

The operation is as follows During the normal operation of the loom,upon arrival of inserting devices 14 and 15 at the pickup point of theflat weft filaments l6 and 17, the thermoelectric element 1 has effecteda downward vertical movement caused by cam 12, placing said element 1 inoperative position (FIG. 1), i.e., at the edges of the two parallelfabrics l8 and 19 between the two vertical planes formed respectively bythe lines of presentation of flat weft filaments 16 and 17 to theinserting devices 14 and 15 and the lines of displacement of saidinserting devices 14 and 15 through the two sheds. 20 and 21. Upon thestart of the return movement of inserting devices 14 and 15 pulling thefilaments 16 and 17, these filaments still joined to the fabrics 18 and19, make contact and wrap around said thermoelectric element 1, and uponcontinuation of the advance of inserting devices 14 and 15, the meltingof the thermoplastic material of flat weft filaments 16 and 17 isproduced automatically, and the filaments are severed.

Upon the complete insertion of filaments l6 and 17 in their respectivesheds 20 and 21, cam 12 causes the upward motion of elbow arm 4 andconsequently of thermoelectric element 1, placing it. in a raisednonoperative position, so as not to obstruct the advance of filaments l6and 17 pushed by comb 22 of slay 23 toward the lines 24 and 25 offormation of fabrics 18 and 19, thus permitting the continuation of thecycle of formation of these fabrics.

Having described the invention, it will be understood that variousmodifications and improvements may be made which come within the scopeof the annexed claims.

I claim:

1. Apparatus for use with a shuttleless loom having at least two fixedweft supplies and reciprocatory weft inserting means for simultaneouslyweaving at least two parallel fabrics, comprising an arm terminating inan elongated thermoelectric element having a length greater than thedistance between all of the fabrics being woven, means for mounting thearm on the frame of a loom for vertical reciprocatory movement between aplurality of operative positions and an inoperative position of thethermoelectric element, cam means for attachment to a rotating elementof a loom in operative engagement with said arm to move the arm betweensaid operative and inoperative positions, said elongated thermoelectricelement being arranged on said arm in vertically extending dispositionwhereby when the arm is in inoperative position said element is entirelyclear of the horizontal plane of the weft filaments and when the armisin any of said operative positions said element intersects thehorizontal plane of all of the weft filaments being moved into the shedof the loom by the weft-inserting means, said weft filaments beingpartially wrapped around said thermoelectric element by continuedinserting movement.

1. Apparatus for use with a shuttleless loom having at least two fixedweft supplies and reciprocatory weft inserting means for simultaneouslyweaving at least two parallel fabrics, comprising an arm terminating inan elongated thermoelectric element having a length greater than thedistance between all of the fabrics being woven, means for mounting thearm on the frame of a loom for vertical reciprocatory movement between aplurality of operative positions and an inoperative position of thethermoelectric element, cam means for attachment to a rotating elementof a loom in operative engagement with said arm to move the arm betweensaid operative and inoperative positions, said elongated thermoelectricelement being arranged on said arm in vertically extending dispositionwhereby when the arm is in inoperative position said element is entirelyclear of the horizontal plane of the weft filaments and when the arm isin any of said operative poSitions said element intersects thehorizontal plane of all of the weft filaments being moved into the shedof the loom by the weft-inserting means, said weft filaments beingpartially wrapped around said thermoelectric element by continuedinserting movement.